Digital picture frames are a mix between a conventional picture frame and a computer display. They look like a regular picture frame, but instead of simply displaying a paper print, they display pictures on a LCD. The advantage is that you can run slide shows of all your favorite pictures instead of displaying just one. The disadvantage is that they are quite expensive even though prices have come down quite a bit. Let's take a look at digital photo frames and what to look out for when you consider buying one.

First, what exactly is a digital picture frame? It is really a basic computer designed for just one task, displaying pictures from digital cameras. Digital frames come in many different styles and sizes. Pictures can be loaded into a digital frame via memory cards, directly from a digital camera, from a computer, over a wireless network or even directly from the Internet. Most are operated via hardware buttons and onscreen menus. Some have remote controls.

Since LCD screens are expensive, the size of the display pretty much determines the cost of the digital frame. Compared to laptop computer screens, which generally measure between 12 and 17 inches diagonally, most digital frames are smaller. While you can get digital frames as large as flatscreen TVs, most have screens in the 7 to 10 inch range. Frames also come in different aspect ratios. Some use the standard 4:3 ratio used in older TVs and computer displays whereas more and more use the newer "wide" format with a 16:9 or 16:10 aspect ratio.

I cannot overemphasize the importance of a good quality LCD. Resolution is obviously important. Older frames had LCDs with inadequate resolution which made for poor picture quality; newer ones often use the same resolution as today's computer screens. Equally or more important is the viewing angle of the screen. Ideally, the picture should remain bright and visible and free of color distortions when viewed from any angle. Older or low-cost frames may have narrow viewing angles.

Make sure the frame supports the type of memory card you use. Almost all frames support the popular SD Cards, but not all of them let you use some of the less common formats such as xD-Picture cards or some of Sony's Memory Sticks. File formats are important as well. All frames support JPEG files, but only higher end frames may support additional formats. Many also support some movie file and audio formats so you can watch movie clips and listen to music as well.

You may have heard of wireless digital picture frames. These have wireless functionality just like most notebook computers. Depending on the type and model, they can link up with the wireless network in your home and use it to connect to your PC or the Web. Some can interact with popular photo sharing services such as Flickr!, Picasa or PhotoBucket. Wireless photo frames are becoming increasingly popular because they easily let you share pictures with friends and family.

Digital frame technology is increasingly used in novel ways and formats. There are picture frames with iPod docking stations, digital frame key chains, frames with integrated printers and more.

In addition to different sizes and technologies, digital frames also come in many elegant designs. You can get very traditional looking wood frames, gleaming metal frames, glass frames, and even replaceable faceplates.

Digital picture frames are a wonderful way to enjoy your photos, and with prices having come down so much, this is a great time to get one (or a few).